Brake fluid pressure control apparatus in skid control system

摘要

A brake fluid pressure control apparatus in a skid control system includes electromagnetic valves arranged between a master cylinder and a wheel cylinder, receiving control signals of a control unit measuring the skid condition of the wheel to control a brake fluid pressure to the wheel cylinder; a hydraulic reservoir reserving the brake fluid discharged through the electromagnetic valves from the wheel cylinder; a pressure fluid supply conduit connecting the master cylinder with the electromagnetic valves and containing a first check valve which allows the flow of fluid in the direction of the electromagnetic valves; a fluid pump for returning brake fluid from the hydraulic reservoir into a portion of the fluid pressure supply conduit between the first check valve and the electromagnetic valves; a pressure fluid return conduit connecting the master cylinder with the wheel cylinder and containing a second check valve which allows the flow of fluid in the direction of the master cylinder; and a controllable check valve device arranged in the pressure fluid supply conduit, including the first check valve and a control portion responsive to a fluid pressure of the master cylinder or the outlet of the fluid pump, the control portion controlling to permit the first check valve to make the free communication between the master cylinder and the electromagnetic valves when the fluid pressure to the control portion is lower than a predetermined pressure.